elec. fan stuck ON

cwm921 · Post by **cwm921** » 06 Aug 2010, 22:23

1999 S80 T6 has 133K miles. The elec. rad. fan drained the battery recently. Stayed running for 2+ hrs. after ignition was shut off. Unplugged connector for fan after we jumped it & got home. Since fan runs continuously, I can rule out a fuse. I pulled each relay in front & rear fuse/relay board one @ a time w/fan plugged in, hoping one would stop fan. No such luck. What would be next in my investigation? Wires going to fan connector are probably 10-12 gauge wire, so I'm guessing there is some switching ckt. to control fan. What gives??

pj8708 · Post by **pj8708** » 07 Aug 2010, 14:42

I have a 07 and know nothing about a 99, but a quick observation would wonder if there musen't be a sensor that tells the fan when to come on and when to shut off according to the radiator temp. When I shut off my 3.2 after a long drive the fan will sometimes stay running after I shut off the car. When the temp. comes down to pre-determined levels the fan shuts off. Maybe you have a bad temp sensor.